Statistics And Probability Question 488

Question: The value of C for which $ P,(X=k)=Ck^{2} $ can serve as the probability function of a random variable X that takes 0, 1, 2, 3, 4 is

[EAMCET 1994]

Options:

A) $ \frac{1}{30} $

B) $ \frac{1}{10} $

C) $ \frac{1}{3} $

D) $ \frac{1}{15} $

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Answer:

Correct Answer: A

Solution:

  •          $ \sum\limits_{k=0}^{4}{P(X=k)}=1\Rightarrow \sum\limits_{k=0}^{4}{Ck^{2}}=1 $                   
    

$ \Rightarrow C(1^{2}+2^{2}+3^{2}+4^{2})=1\Rightarrow C=\frac{1}{30} $ .